You must have some really POS systems is all I can say. I can still run my old (1997) Dell 1.2 Ghz PIII (upgraded from 650 Mhz), 768 mb RAM (upgraded from 512 Mhz) with a 32 Mb Ge-Force MX-440 (upgraded from 16 Mhz Voodoo) at 35 fps with all graphics setting on low. I'm just surprised the old 250W Foxcon PSU hasn't died yet.
Nah, just higher expectations. At 35 fps with everything turned off what happens when you arrive at a place full of smoke? When a set of buffs happens to fly by with an engine smoking or firing its tracers? Mine starts at 60fps and when it gets bz and in the 30s, it is unplayable by MY standards.
So it comes down to personal preferences. Dog-fighting low and slow when fps drops in the 30s is horrible and hitting anything almost impossible. Drop bellow 30 and fighting is not an option. Can you drop a bomb from 30K at 20fps and have fun doing it? Absolutely, if that is how you play, but some things are impossible at low fps.
I have been through many computers in the last 10 years here. After I get a new one, everything runs perfectly. Then the upgrades come and within a year I have to turn everything off. Then fps drops until a new video card is required and eventually a new computer. Depending on your stile of play, you may need a new box every 1 to 2 years depending on the upgrades (if you want to see the new stuff).